Hybrid composite-metal energy absorbing seat

ABSTRACT

A hybrid composite-metal energy absorbing seat is described. According to one embodiment, an aircraft seat includes a seat base assembly and a seat back assembly. The seat base assembly includes multiple rigid metal seat base side frame elements joined by a lower seat pan, an energy absorbing element placed on the lower seat pan to deform and absorb downward energy in a crash, and a contoured seat pan whose sides extend past the seat base side frame elements and deform to absorb downward energy in a crash. The seat back assembly is attached to the seat base assembly and includes multiple rigid metal seat back side frame elements joined by a contoured composite seat back. The rigid metal seat back side frame elements absorb forward crash load energy by permanently deforming during a severe forward crash load. The contoured composite seat back provides design/aesthetic flexibility.

This application claims the benefit of U.S. Provisional Application No.60/373,986, filed Apr. 19, 2002 and U.S. Provisional Application No.60/378,195, filed May 6, 2002; U.S. Utility Patent Application No.10/420,566, all of which are hereby incorporated by reference in theirentirety.

COPYRIGHT NOTICE

Contained herein is material that is subject to copyright protection.The copyright owner has no objection to the facsimile reproduction ofthe patent disclosure by any person as it appears in the Patent andTrademark Office patent files or records, but otherwise reserves allrights to the copyright whatsoever.

BACKGROUND

1. Field

Embodiments of the present invention generally relate to a simple,lightweight and affordable seat structure. More particularly,embodiments of the present invention relate to a hybrid composite-metalseat assembly intended for use as an energy absorbing aircraft seat andmeeting the current Federal Aviation Regulations (FAR) Part 23 normalcategory aircraft requirements (“FAR Part 23”).

2. Description of the Related Art

Conventional aluminum seats have numerous expensive small components,which contribute to excessive assembly time and increased cost. Inaddition, it is often difficult to form the complex geometry that mightbe preferred for interior styling.

Although composite seats are less expensive to assemble and can be usedto form complex shapes, there is insufficient design data relating tocrash/high-speed deformation environments. Also contributing to theinavailability of crash test data is that fact that composites don'tplastically deform—thus making crash reaction calculations difficult.

SUMMARY

A hybrid composite-metal energy absorbing seat is described. Embodimentsof the present invention seek to provide an improved seat which findsparticular usefulness in aircraft applications, and which includes anovel force dissipation assembly. According to one embodiment, the seatincludes a seat base assembly and a seat back assembly. The seat baseassembly includes multiple rigid metal seat base side frame elementsjoined by a seat pan assembly and covered with a seat pan cover. Anenergy absorbing element in the seat pan assembly serves as a downwardload energy absorber to absorb severe downward crash load energy.Additionally, deformation of the seat pan cover also serves to absorbdownward crash load energy. These two mechanisms can be used together orindividually depending upon the energy absorption requirements of theseat environment. The seat back assembly is attached to the seat baseassembly. The seat back assembly includes multiple rigid metal seat backside frame elements joined by a contoured composite seat back. The rigidmetal seat back side frame elements absorb forward crash load energy bypermanently deforming during a severe forward crash load. The contouredcomposite seat back and contoured composite seat pan providedesign/aesthetic flexibility.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Embodiments of the present invention are illustrated by way of example,and not by way of limitation, in the figures of the accompanyingdrawings and in which like reference numerals refer to similar elementsand in which:

FIG. 1A depicts a crew seat assembly according to one embodiment of thepresent invention.

FIG. 1B is an exploded view of the crew seat assembly of FIG. 1.

FIG. 2 is a partially exploded view of a portion of a seat base assemblyaccording to one embodiment of the present invention.

FIG. 3 depicts a side view of a seat base side frame element accordingto one embodiment of the present invention.

FIG. 4 depicts a side view of a seat base side frame element accordingto an alternative embodiment of the present invention.

FIG. 5 depicts a trimetric view of a molded seat pan cover according toone embodiment of the present invention.

FIG. 6 depicts a trimetric view of a lower seat pan according to oneembodiment of the present invention.

FIG. 7 depicts a trimetric view of a seat energy absorber assemblyaccording to one embodiment of the present invention.

FIG. 8 is an exploded view of a portion of a seat back assemblyaccording to one embodiment of the present invention.

FIG. 9 depicts a trimetric view of a molded inner seat back shellaccording to one embodiment of the present invention.

FIG. 10 depicts a trimetric view of a molded outer seat back shellaccording to one embodiment of the present invention.

FIG. 11A depicts a side view of a seat back side frame element accordingto one embodiment of the present invention.

FIG. 11B depicts a front view of a seat back side frame elementaccording to one embodiment of the present invention.

FIG. 12 depicts a seat back side frame element according to analternative embodiment of the present invention.

DETAILED DESCRIPTION

A cost effective hybrid composite-metal energy absorbing aircraft seatis described that provides a strong, lightweight structure for enhancedoccupant safety. Broadly stated, embodiments of the present inventionseek to achieve an appropriate combination of composite and metal partsin a way that meets current FAR Part 23 requirements while reducing partcount, part cost and assembly cost to provide an affordable aircraftseat.

Embodiments of the present invention also seek to provide a seat whichincludes a portion having a deformable core, and wherein the seatfurther includes an assembly which engages the deformable core during amishap, or crash, thereby further dissipating some of the force of thecrash.

Embodiments of the present invention may be manufactured as originalequipment, or alternatively may be manufactured in the nature of aretrofit. A goal of various embodiments of the present invention is toprovide a seat which is relatively simple in design, easy to install,and which requires no substantial alteration of the cabin of theaircraft to accommodate installation.

Embodiments of the present invention also provide aesthetic flexibilityto seat designers by maintaining seat back loads primarily in rigidmetal side members, thereby allowing the shape of the composite seatback to be customized aesthetically without significantly affectingcrashworthiness of the seat.

An object of one embodiment of the present invention is to provide aseat having a force dissipation assembly which is lightweight, compact,efficient, and further can be purchased at a relatively nominal price.

An object of one embodiment of the present invention is to provide aseat which is characterized by ease of utilization, simplicity ofconstruction, and which further operates in the absence of externalsources of power.

An object of one embodiment of the present invention is to provideimproved elements and arrangements thereof in a seat for the purposesdescribed and which is dependable, economical and durable.

According to one embodiment, a simple seat pan assembly serves as adownward load energy absorber to absorb severe downward crash loadenergy. For example, an energy absorber may be contained within a simplelower seat pan or a contoured seat pan cover may be placed over the tworigid seat base sides or a combination of both an energy absorber and acontoured seat pan cover may be employed.

According to one embodiment, metal parts, such as aluminum, are used forcomponents of the seat assemblies that need to plastically deform in apredictable manner whereas composite materials, such as carbon fiber,are used for complex shaped components of the seat that do not need toplastically deform and for integration of multiple structural elementsinto a single component. Advantageously, in this manner, a seat can beprovided that enhances occupant safety and can be produced, constructed,and installed relatively inexpensively while allowing for a variety ofaesthetically pleasing shapes to be achieved. Other features ofembodiments of the present invention will be apparent from theaccompanying drawings and from the description that follows.

In the following description, for the purposes of explanation, numerousspecific details are set forth in order to provide a thoroughunderstanding of embodiments of the present invention. It will beapparent, however, to one skilled in the art that various embodiments ofthe present invention may be practiced without some of these specificdetails. In other instances, well-known structures and devices are shownin block diagram form.

For convenience, embodiments of the present invention are described withreference to a crew aircraft seat. However, embodiments of the presentinvention are thought to be equally applicable in various otherenvironments, such as aircraft passenger (main cabin area) seats,helicopter seats, flight attendant seats, ejection seats of fighteraircraft, automobiles, including trucks, racing cars, buses, watercraft,trains and the like. Consequently, while embodiments of the presentinvention are thought to be particularly useful in aircraft andspecifically in the cockpit, the present invention is not limited toapplication within any particular environment. Additionally, whileembodiments of the present invention are described with reference to aparticular lamination methodology, those skilled in the field ofcomposites will readily understand that various other compositeprocessing technologies may be employed, including, but not limited tothermoset resin injection pultrusion (RIP), thermoplastic pultrusion,prepreg formation, sheet/bulk molding compounds (SMC/BMC) compressionmolding, injection-compression molding, preforming of thermoformablefabrics, compression molding of thermoplastic composites, transfermolding, squeezing flow rheology, wet layup, prepreg, RTM, VARTM, orother standard composite manufacturing processes.

Finally, while in the embodiments described herein the primary forwardload energy absorption is accomplished by rigid metal seat back sideframe elements and seat base side frame elements, this new energyabsorption technique may be combined with more traditional seat energyabsorbing devices like deforming legs (see, e.g., U.S. Pat. Nos.5,662,376 and 5,482,351), shock absorbers in legs, etc. to create aneven more effective energy absorbing seat.

Terminology

Brief definitions of terms used in this application are given below.

The term “composite” generally refers to a material created by themacroscopic combination of two or more distinct materials (e.g., areinforcing element or filler and a compatible matrix binder) to obtainspecific characteristics and properties. The components of a composite,typically fibers and resin, retain their identities; that is, they donot dissolve or merge completely into one another. Examples ofcomposites include, but are not limited to, carbon fiber reinforcedepoxy prepreg, glass fiber reinforced epoxy prepreg, and othercombinations of fibers and resins or matrix materials. Such combinationsinclude glass, carbon, boron, Kevlar™, aramid, and other fibers orfiberous materials along with epoxy, polyester, vinylester, nylon, ABS,PPS, PEEK, and other thermosetting or thermoplastic matrix materials.

The terms “connected”, “coupled” or “joined” and related terms are usedin an operational sense and are not necessarily limited to a directconnection or coupling.

The phrases “in one embodiment,” “according to one embodiment,” and thelike generally mean the particular feature, structure, or characteristicfollowing the phrase is included in at least one embodiment of thepresent invention, and may be included in more than one embodiment ofthe present invention. Importantly, such phrases do not necessarilyrefer to the same embodiment.

If the specification states a component or feature “may”, “can”,“could”, or “might” be included or have a characteristic, thatparticular component or feature is not required to be included or havethe characteristic.

The term “laminate” generally refers to a composite structure composedof multiple layers of cloth, fabric, and/or unidirectional tape andresin, laminated or bonded together.

The term “responsive” includes completely or partially responsive.

The term “truss” generally refers to a rigid frame of members in tensionand compression joined to form a series of triangles, other stableshapes, or a combination thereof. A truss is characterized by openconstruction that is lighter than, yet just as strong as, a beam with asolid web between upper and lower lines. A thin web may be used incombination with a truss structure to simplify manufacturing, provideadditional strength and stiffness, or provide additional attachmentpoints than a traditional truss.

The term “energy absorber” generally refers to any material or materialform that absorbs dynamic energy without significant rebound followingimpact. For example, water is an energy absorber since a ball will notbounce very high if dropped onto a surface of water. Energy absorbingmaterials used in the context of this patent include, but are notlimited to, aluminum honeycomb (some of which is specifically tailoredfor improved energy absorbing characteristics, but even standardaluminum honeycomb absorbs energy well when crushed), honeycombs ofother materials such as Nomex™, carbon, Kevlar™ or even paper, many openor closed-cell foams, or viscoelastic materials as those sold by OregonAero, EAR Corp, 3M, and many others.

The term “metal” generally refers to, but is not limited to, commonaerospace materials such as 2024, 6061, and 7075 aluminum in varioustempers, along with steels such as 4130, 301, and 17-4PH.

FIGS. 1A and 1B depict a crew seat assembly 100 according to oneembodiment of the present invention. In the embodiment depicted, thecrew seat assembly 100 includes an upper seat back assembly 110 and alower seat (seat base) assembly 120. For clarity, foam and leatherlayers that would ordinarily be included for comfort and aesthetics arenot shown.

The upper seat back assembly 110 and the lower seat assembly 120 aretypically either pinned or bolted to allow a fixed seat back position ora foldable seat back. In the example depicted, the seat back assembly110 and the seat base assembly 120 are attached at a primary seat backpivot (hinge) point 111 and the upper seat back assembly 110 is lockedin place with a pin assembly at a primary seat back latch point 112. Pinassembly can include a mechanism that allows one of the two pins to pullout of joint and allow seat back to fold down. Additionally, severalpinning locations would allow the seat back to be adjusted to severalseat back angles for comfort.

The seat base assembly 120 includes two rigid seat base side frameelements 122 and a seat pan assembly, including a lower seat pan 123,which may contain an optional seat energy absorber assembly 150, and amolded upper seat pan cover 125. According to one embodiment, the seatpan assembly serves as a downward load energy absorber to absorb severedownward crash load energy. For example, an energy absorber may becontained within the lower seat pan 123 or the molded upper seat pancover 125 may be placed over the two rigid seat base sides 122 or acombination of both the seat energy absorber assembly 150 and the seatpan cover 125 may be employed. Further details regarding these andvarious other parts and their functions are provided below.

The upper seat back assembly 110 includes two rigid seat back side frameelements 115 joined together by a molded inner seat back shell 105 and amolded outer seat back shell 140. The molded inner seat back shell 105and the molded outer seat back shell 140 house an integrated shoulderbelt harness system, including an inertia reel 130, and shoulder belt135 attached to the upper seat assembly with the inertia reel strap 135.

FIG. 2 is a partially exploded view of a portion of a seat base assembly200 according to one embodiment of the present invention. In theembodiment depicted, the seat base assembly 200 includes two rigid seatbase side frame elements 222, a seat pan 223, and a seat energy absorberassembly 250.

The seat base side frame elements 222 and lower seat pan 223 maintainappropriate rigidity in the presence of normal forward loads and are notrequired to deform plastically in an emergency situation to absorbenergy. The seat base side frame elements 222 may be machined out ofaluminum plates to form rigid trussed structures.

The seat pan 223 is interposed between the two seat base side frameelements 222 and positioned substantially under the base of theoccupant's spinal column.

According to the embodiment depicted, the box formed by the lower seatpan 223 allows for insertion of the seat energy absorber assembly 250which comprises “crush zone” material to prevent spinal injury andabsorbs downloads.

In alternative embodiments, the seat energy absorber assembly 250 is notincluded and download energy absorption is addressed by the molded seatpan cover 125 and/or other energy absorption devices.

FIG. 3 depicts a side view of a seat base side frame element 322according to one embodiment of the present invention. In this example,the seat base side frame elements 322 are trussed and may be machinedout of 0.75″ aluminum plate to form a rigid truss or webbed truss havingmultiple triangular shaped recesses 311-315 with members havingthickness on the order of approximately 0.125″ to 0.25″. In alternativeembodiments, the seat base side frame element 322 may not be trussed.Furthermore, other metals or alloys may be employed, the metal plate maybe on the order of approximately 0.5″ to 1″, and other stable shapes maybe formed by the recesses.

According to one embodiment, the seat base side frame elements incombination with the seat back side frame elements are the primaryforward load absorption mechanism. For example, both pairs of side frameelements may absorb forward crash load energy by permanently deformingduring a severe forward crash load.

Various other arrangements and combinations of trussed structures arecontemplated. FIG. 4 depicts a side view of a seat base side frameelement according to an alternative embodiment of the present invention.Other combinations necessary to group multiple seats together, ascommonly found in an airliner with 2, 3, or more seats in a row, arealso envisioned.

FIG. 5 depicts a trimetric view of a molded seat pan cover 525 accordingto one embodiment of the present invention. In this embodiment, themolded seat pan cover includes sides 535 configured to extend across therigid seat base side frame elements 122 to provide energy absorptioncapability in a download by deforming up and over the rigid seat baseside frame elements and allowing a center portion 540 of the moldedcomposite seat cover to deflect downwards.

According to one embodiment, the molded seat pan cover 525 is lightlyfastened by fasteners to the plurality of rigid seat base side frameelements with the fasteners which shear out in a download. In anotherembodiment, the molded seat pan cover is not fastened to the rigid seatbase side frame elements. According to one embodiment, the molded seatpan cover 525 is fabricated of composite materials, such as carbonfiber. In such a case, materials and fiber orientations are used suchthat the composite seat pan cover 525 has desired download energyabsorbing capabilities, including delaminations, during a severedownward crash load as the sides of the cover deform up and over thesides of the rigid metal seat base side frame elements. In oneembodiment, the molded seat pan cover 525 serves as the primary downloadenergy absorber. In other embodiments, additional download energyabsorption components are included to work in cooperation with thecomposite molded seat pan cover 525 or are provided as a substitute fordownload energy absorption capabilities in the composite molded seat pancover 525.

According to an alternate embodiment, the molded seat pan cover 525 isfabricated of metal, such as a plastically formed aluminum sheet. Thisis particularly appropriate for certain high rate production situations.This metal seat pan cover would also absorb energy as the sides of thepan deform up and over the sides of the rigid metal seat base side frameelements.

FIG. 6 depicts a trimetric view of a seat pan 623 according to oneembodiment of the present invention. According to one embodiment, theseat pan 623 is formed of sheet metal, such as 0.063″ aluminum sheet.Alternatively, the seat pan 623 may be fabricated of compositematerials, such as carbon fiber.

FIG. 7 depicts a trimetric view of a seat energy absorber assembly 750according to one embodiment of the present invention. Depending upon theparticular design constraints of the seat, the download energy absorbermay comprise a block of honeycomb made of aluminum, Nomex™ material,carbon, Kevlar™ material, paper or a variety of other honeycomb or foammaterials with energy absorbing characteristics. According to oneembodiment, the download energy absorber is a block of open orclosed-cell foam or a block of viscoelastic materials.

FIG. 8 is an exploded view of a portion of a seat back assembly 800according to one embodiment of the present invention. In the portion ofthe embodiment depicted, the seat back assembly 800 includes two seatback support frame elements 815, a molded outer seat back shell 840, andan integrated shoulder belt harness system including an inertia reel 830and shoulder belt 835 attached to an inertia reel strap 845, shoulderstrap guide/headrest retainer 850, and a shoulder belt 835.

As mentioned above, according to one embodiment, metal parts are usedfor components of the seat that for which it is desirable to haveplastically deform in a predictable manner whereas composite materials,such as carbon fiber, are used for complex shaped components of the seatthat do not need to plastically deform and for integration of multiplestructural elements into a single component.

In some embodiments, the seat back side elements are fabricated ofcomposite materials or are integrated into a reduced part-count orsingle piece seat back assembly. In such instances, materials and fiberorientations are used such that the composite seat back has energyabsorbing capabilities similar to the metal seat back side frameelements 815 which absorb energy by permanently deforming during asevere forward crash load.

According to one embodiment, the seat back side frame elements 815 areattached to the molded outer seat back shell 840 with rivets, machinescrews and/or the like. The seat back side frame elements 815 aredesigned to provide predictable plastic deformation under emergencysituations.

The molded outer seat back shell 840 and the molded inner seat backshell 105 together form a housing for the integral shoulder belt harnesssystem to conceal and protect the inertia reel 830 and shoulder harness835. The molded outer seat back shell 840 and the molded inner seat backshell 105 together also serve to provide stability to the seat back sideframe elements 815 during emergency situations by keeping the seat backside frame elements 815 aligned appropriately for plastic deformationand preventing undesired rotation and folding. This stability isprovided when subjected to either forward or aft facing crash loads,thus seats incorporating these designs may be installed facing eitherforward or aft in the vehicle.

In the embodiment depicted, due to the positioning and attachment of theinertia reel 830 internal to the molded outer seat back shell 840 andseat back support frame elements 815, the primary shoulder belt crashloads stay in the seat back side frame elements 815 and down through theseat back hinge/latch points into the seat base side frame elements 122thereby allowing for appropriate plastic deformations in crashscenarios.

In one embodiment, adjustable shoulder belts are rigidly attached to theshoulder belt guide 850, eliminating the inertia reel and inertia reelstrap.

FIG. 9 depicts a trimetric view of a molded inner seat back shell 905according to one embodiment of the present invention. According to oneembodiment, the molded inner seat back shell 905 is fabricated ofcomposite materials, such as carbon fiber. Advantageously, in thismanner, the inner seat back shell 905 provides design/aestheticflexibility by allowing contours and/or complex geometry to be formedthat might be preferred for interior styling.

Notably, in addition to the design flexibility provided, composites havea very high potential for absorbing kinetic energy during a crash (mostbullet proof vests are made of composites). The composite energyabsorption capability offers a unique combination of reduced structuralweight with an increases crash resistance compared to metallicstructures. Consequently, embodiments of the present invention arecontemplated in which the seat back becomes a single composite piece(instead of the current metal seat back sides and composite seat back)and much of the seat base is combined into a single composite piece(containing the seat base sides and lower seat pan). The variouscomposite structures described herein may be formed of laminate, e.g.,multiple layers of composite materials, such as carbon fiber, laminatedtogether. In one embodiment, the carbon fiber structure is comprised ofa laminated prepreg composite structure having a service temperature of180° F.

In the embodiment depicted, the molded inner seat back shell 905includes sides 910 configured to extend across the rigid seat back sideframe elements 115 to provide stability to the seat back side frameelements 115 during emergency situations by keeping the seat back sideframe elements 115 aligned appropriately for plastic deformation andpreventing undesired rotation and folding. Additionally, the sides 910provide energy absorption capability in crash loads when the seat isinstalled facing the opposite direction by deforming up and over therigid seat back side frame elements 115 and allowing a center portion ofthe molded seat back shell 905 to deflect inward. Consequently, bothenergy absorption and stability are provided when subjected to eitherforward or aft facing crash loads and seats incorporating embodiments ofthe present invention may be installed facing either forward or aft inthe vehicle.

FIG. 10 depicts a trimetric view of a molded outer seat back shell 1040according to one embodiment of the present invention. Typically, it willbe convenient to form the molded inner seat back shell 1040 of the samematerial employed for the outer seat back shell 905. However, inalternative embodiments, different materials and/or composite processingtechniques may be used depending on the design constraints.

According to one embodiment, the molded outer seat back shell 1040 isfabricated of composite materials, such as carbon fiber. Advantageously,as above, the outer seat back shell 1040 also provides fordesign/aesthetic flexibility by allowing contours and/or complexgeometry to be formed that might be preferred for interior styling.

In the embodiment depicted, the molded outer seat back shell 1040 alsoincludes sides 1010 configured to extend across the rigid seat back sideframe elements 115 to provide stability to the seat back side frameelements 115 during emergency situations by keeping the seat back sideframe elements 115 aligned appropriately for plastic deformation andpreventing undesired rotation and folding.

FIGS. 11A and 11B depicts side and front views, respectively, of a seatback side frame element 1115 according to one embodiment of the presentinvention. In one embodiment, the seat back side frame elements 1115 areformed from a 0.25″ sheet of metal, such as aluminum, mixed metals, or ametallic alloy, such as steel. In this manner, the seat back supportframe elements 1115 may be easily altered to accommodate interior spaceneed and/or aesthetic purposes. In alternative embodiments, the seatback support frame elements 1115 may be machined from a thicker metalplate to form a truss-like structure as shown in FIG. 12, for example.

As can be seen from the side view, in the embodiment depicted, the seatback side frame elements 1115 are shaped to accommodate the tapered formof the overall upper seat back assembly 110 while maintainingappropriate rigidity in the presence of forward and aft loads.

FIG. 12 depicts a seat back side frame element 1215 according to analternative embodiment of the present invention. According to thisembodiment, the seat back side frame elements 1215 are machined out of0.75″ aluminum plates forming rigid truss structures having multipletriangular recesses 1221-1225 with members having thickness on the orderof approximately 0.06″ to 0.25″. In alternative embodiments, othermetals or alloys may be employed, the plates may be on the order ofapproximately 0.5″ to 1″, and other stable shapes may be formed by therecesses.

In the foregoing specification, the invention has been described withreference to specific embodiments thereof. It will, however, be evidentthat various modifications and changes may be made thereto withoutdeparting from the broader spirit and scope of the invention. One of thefeatures of this energy absorbing seat design is its ability to bemodified according to aesthetic preferences, while retaining basic seatcrashworthiness and energy absorbing capabilities. The specification anddrawings are, accordingly, to be regarded in an illustrative rather thana restrictive sense.

1. An energy absorbent seat comprising: a seat base assembly, whereinthe seat base assembly includes a plurality of rigid seat base sideframe elements joined by a seat pan assembly, wherein at least one ofthe plurality of seat base side frame elements is designed to absorbforward crash energy through inelastic deformation, and wherein the seatpan assembly is designed to absorb downward crash energy throughinelastic deformation; and a seat back assembly attached to the seatbase assembly, wherein the seat back assembly includes a plurality ofrigid seat back side frame elements joined by a seat back, wherein atleast one of the plurality of rigid seat back side frame elements isdesigned to absorb forward crash energy through inelastic deformation.2. The seat of claim 1, wherein the seat pan assembly includes a blockof honeycombed material, and wherein the block of honeycombed materialis capable of absorbing energy by inelastic deformation.
 3. The seat ofclaim 2, wherein the block of honeycombed material is aluminum.
 4. Theseat of claim 3, wherein at least one side of the block of aluminumhoneycombed material is bonded to a sidewall.
 5. The seat of claim 2,wherein the honeycomb openings of the block of honeycomb material arealigned such that they form a plane approximately parallel to a seatingsurface.
 6. An aircraft seat, wherein the aircraft seat comprises: aseat base assembly designed to absorb both forward energy and downwardenergy of the magnitude exhibited in an aircraft crash; and a seat backassembly attached to the seat base assembly, wherein the seat backassembly is designed to absorb forward energy of the magnitude exhibitedin an aircraft crash.
 7. The aircraft seat of claim 6, wherein the seatbase assembly is designed to permanently deform when exposed to at leastone of the forward energy and the downward energy, and wherein thedeformation absorbs energy.
 8. The aircraft seat of claim 6, wherein theseat back assembly is designed to permanently deform when exposed to theforward energy, and wherein the deformation absorbs energy.
 9. Theaircraft seat of claim 7, wherein the seat base assembly includes ablock of honeycomb aluminum material.
 10. The aircraft seat of claim 6,wherein a first sidewall is attached to a first side of the block ofhoneycomb aluminum material, and wherein a second sidewall is attachedto an opposing side of the honeycomb aluminum material.
 11. The aircraftseat of claim 6, wherein the first sidewall covers honeycomb openings inthe aluminum honeycombed material.
 12. A hybrid composite-metal energyabsorbing seat comprising: a seat base assembly, wherein the seat baseassembly includes a plurality of rigid metal seat base side frameelements joined by a seat pan assembly, and wherein the plurality ofrigid metal seat base side frame elements are designed to absorb forwardcrash energy by permanently deforming and; and a seat back assemblyattached to the seat base assembly, wherein the seat back assemblyincludes a plurality of rigid metal seat back side frame elementsjointed by a contoured composite seat back, the plurality of rigid metalseat back side frame elements to absorb forward crash load energy bypermanently deforming during a severe forward crash load, the contouredcomposite seat back providing design/aesthetic flexibility.
 13. The seatof claim 12, wherein the seat pan assembly is designed to permanentlydeform when exposed to a downward crash energy.
 14. The seat of claim13, wherein the seat pan assembly includes a seat pan and a block ofenergy absorbing material.
 15. The seat of claim 14, wherein the blockof energy absorbing material is a block of honeycombed material.
 16. Theseat of claim 15, wherein the block of honeycombed material is selectedfrom a group consisting of: aluminum, paper, carbon, Nomex™, andKevlar™.
 17. The seat of claim 12, wherein the rigid metal seat baseside frame elements comprise trusses or webbed trusses having formedtherein a plurality of recesses having stable shapes to reduce theweight of the rigid metal seat base side frame elements whilemaintaining strength of the rigid metal seat base side frame elements.18. The seat of claim 12, wherein the rigid metal seat back side frameelements comprise webbed trusses having formed therein a plurality ofrecesses having stable shapes to reduce the weight of the rigid metalseat back side frame elements while maintaining strength of the rigidmetal seat back side frame elements.
 19. The seat of claim 12, whereinthe seat pan assembly includes a molded composite seat cover havingsides extending across the plurality of rigid metal seat base side frameelements to provide energy absorption capability in a download bydeforming up and over the plurality of rigid metal seat base side frameelements and allowing a center portion of the molded composite seatcover to deflect downwards.
 20. The seat of claim 19, wherein the moldedcomposite seat cover is lightly fastened by fasteners to the pluralityof rigid metal seat base side frame elements with the fasteners shearingout when exposed to a downward crash energy.
 21. The seat of claim 19,wherein the molded composite seat cover is not fastened to the pluralityof rigid metal seat base side frame elements.
 22. An aircraft seatcomprising: a seat base assembly including at least two rigid metal seatbase side frame elements joined by a seat pan assembly, wherein the seatbase assembly is designed to permanently deform in a severe aircraftcrash; and a seat back assembly attached to the seat base assembly. 23.The aircraft seat of claim 22, wherein the seat pan assembly includes amolded composite seat cover having sides extending across the pluralityof rigid metal seat base side frame elements to provide energyabsorption capability in a download by deforming up and over theplurality of rigid metal seat base side frame elements and allowing acenter portion of the molded composite seat cover to deflect downwards.24. The aircraft seat of claim 22, wherein the seat pan assemblyincludes a block of honeycombed material, wherein the block ofhoneycombed material is capable of absorbing energy by inelasticdeformation.
 25. The aircraft seat of claim 24, wherein the block ofhoneycombed material is aluminum.
 26. The aircraft seat of claim 25,wherein at least one side of the block of aluminum honeycombed materialis bonded to a sidewall.
 27. The aircraft seat of claim 24, wherein thehoneycomb openings of the block of honeycomb material are aligned suchthat they form a plane approximately parallel to a seating surface. 28.The aircraft seat of claim 22, wherein the seat pan assembly includes adownload energy absorber comprising a block of honeycomb comprising oneor more of Nomex™ material, carbon, Kevlar™ material, and paper.
 29. Theaircraft seat of claim 22, wherein the seat base assembly is furtherdesigned to permanently deform to absorb a forward crash load energyassociated with an aircraft crash.
 30. The aircraft seat of claim 22,wherein the seat back assembly comprises a plurality of rigid metal seatback side frame elements joined by a contoured composite seat back, theplurality of rigid metal seat back side frame elements to absorb forwardcrash load energy by permanently deforming during an aircraft crash. 31.A seat assembly comprising: a seat base energy absorber, wherein theseat base energy absorber includes a block of honeycombed material,wherein the block of honeycombed material is designed to inelasticallydeform in an aircraft crash; and wherein a sidewall is attached to aside of the block of honeycombed material.